This invention relates to plasma etching devices of the type using radio frequency energy to provide a plasma for the etching vapor.
Plasma etching devices are well-known. They provide a means for etching with plasma materials that otherwise are etched by processes involving deposition of etching materials in liquid form. U.S. Pat. No. 3,879,597 issued to Bersin et al., on Apr. 22, 1975 describes a plasma etching device that develops a plasma of the etchant that achieves uniform etching and does so in a rapid and effective manner. However, the plasma generated by the RF energy surrounding the wafer material to be processed causes a harmful plasma manifested as a blue haze whose ultraviolet (UV) radiation often damages the wafers and thereby reduces the yield of the device being processed. There is a need in the field for a system of that type that reduces and inhibits the deleterious radiation effects developed by the plasma.